Search Results

Search found 10850 results on 434 pages for 'shihab returns'.

Page 388/434 | < Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >

• F# for the C# Programmer

  - by mbcrump

  Are you a C# Programmer and can’t make it past a day without seeing or hearing someone mention F#?  Today, I’m going to walk you through your first F# application and give you a brief introduction to the language. Sit back this will only take about 20 minutes. Introduction Microsoft's F# programming language is a functional language for the .NET framework that was originally developed at Microsoft Research Cambridge by Don Syme. In October 2007, the senior vice president of the developer division at Microsoft announced that F# was being officially productized to become a fully supported .NET language and professional developers were hired to create a team of around ten people to build the product version. In September 2008, Microsoft released the first Community Technology Preview (CTP), an official beta release, of the F# distribution . In December 2008, Microsoft announced that the success of this CTP had encouraged them to escalate F# and it is now will now be shipped as one of the core languages in Visual Studio 2010 , alongside C++, C# 4.0 and VB. The F# programming language incorporates many state-of-the-art features from programming language research and ossifies them in an industrial strength implementation that promises to revolutionize interactive, parallel and concurrent programming. Advantages of F# F# is the world's first language to combine all of the following features: Type inference: types are inferred by the compiler and generic definitions are created automatically. Algebraic data types: a succinct way to represent trees. Pattern matching: a comprehensible and efficient way to dissect data structures. Active patterns: pattern matching over foreign data structures. Interactive sessions: as easy to use as Python and Mathematica. High performance JIT compilation to native code: as fast as C#. Rich data structures: lists and arrays built into the language with syntactic support. Functional programming: first-class functions and tail calls. Expressive static type system: finds bugs during compilation and provides machine-verified documentation. Sequence expressions: interrogate huge data sets efficiently. Asynchronous workflows: syntactic support for monadic style concurrent programming with cancellations. Industrial-strength IDE support: multithreaded debugging, and graphical throwback of inferred types and documentation. Commerce friendly design and a viable commercial market. Lets try a short program in C# then F# to understand the differences. Using C#: Create a variable and output the value to the console window: Sample Program. using System;   namespace ConsoleApplication9 {     class Program     {         static void Main(string[] args)         {             var a = 2;             Console.WriteLine(a);             Console.ReadLine();         }     } } A breeze right? 14 Lines of code. We could have condensed it a bit by removing the “using” statment and tossing the namespace. But this is the typical C# program. Using F#: Create a variable and output the value to the console window: To start, open Visual Studio 2010 or Visual Studio 2008. Note: If using VS2008, then please download the SDK first before getting started. If you are using VS2010 then you are already setup and ready to go. So, click File-> New Project –> Other Languages –> Visual F# –> Windows –> F# Application. You will get the screen below. Go ahead and enter a name and click OK. Now, you will notice that the Solution Explorer contains the following: Double click the Program.fs and enter the following information. Hit F5 and it should run successfully. Sample Program. open System let a = 2        Console.WriteLine a As Shown below: Hmm, what? F# did the same thing in 3 lines of code. Show me the interactive evaluation that I keep hearing about. The F# development environment for Visual Studio 2010 provides two different modes of execution for F# code: Batch compilation to a .NET executable or DLL. (This was accomplished above). Interactive evaluation. (Demo is below) The interactive session provides a > prompt, requires a double semicolon ;; identifier at the end of a code snippet to force evaluation, and returns the names (if any) and types of resulting definitions and values. To access the F# prompt, in VS2010 Goto View –> Other Window then F# Interactive. Once you have the interactive window type in the following expression: 2+3;; as shown in the screenshot below: I hope this guide helps you get started with the language, please check out the following books for further information. F# Books for further reading   Foundations of F# Author: Robert Pickering An introduction to functional programming with F#. Including many samples, this book walks through the features of the F# language and libraries, and covers many of the .NET Framework features which can be leveraged with F#.       Functional Programming for the Real World: With Examples in F# and C# Authors: Tomas Petricek and Jon Skeet An introduction to functional programming for existing C# developers written by Tomas Petricek and Jon Skeet. This book explains the core principles using both C# and F#, shows how to use functional ideas when designing .NET applications and presents practical examples such as design of domain specific language, development of multi-core applications and programming of reactive applications.

  Read the article

• Advanced donut caching: using dynamically loaded controls

  - by DigiMortal

  Yesterday I solved one caching problem with local community portal. I enabled output cache on SharePoint Server 2007 to make site faster. Although caching works fine I needed to do some additional work because there are some controls that show different content to different users. In this example I will show you how to use “donut caching” with user controls – powerful way to drive some content around cache. About donut caching Donut caching means that although you are caching your content you have some holes in it so you can still affect the output that goes to user. By example you can cache front page on your site and still show welcome message that contains correct user name. To get better idea about donut caching I suggest you to read ScottGu posting Tip/Trick: Implement "Donut Caching" with the ASP.NET 2.0 Output Cache Substitution Feature. Basically donut caching uses ASP.NET substitution control. In output this control is replaced by string you return from static method bound to substitution control. Again, take a look at ScottGu blog posting I referred above. Problem If you look at Scott’s example it is pretty plain and easy by its output. All it does is it writes out current user name as string. Here are examples of my login area for anonymous and authenticated users:    It is clear that outputting mark-up for these views as string is pretty lame to implement in code at string level. Every little change in design will end up with new version of controls library because some parts of design “live” there. Solution: using user controls I worked out easy solution to my problem. I used cache substitution and user controls together. I have three user controls: LogInControl – this is the proxy control that checks which “real” control to load. AnonymousLogInControl – template and logic for anonymous users login area. AuthenticatedLogInControl – template and logic for authenticated users login area. This is the control we render for each user separately because it contains user name and user profile fill percent. Anonymous control is not very interesting because it is only about keeping mark-up in separate file. Interesting parts are LogInControl and AuthenticatedLogInControl. Creating proxy control The first thing was to create control that has substitution area where “real” control is loaded. This proxy control should also be available to decide which control to load. The definition of control is very primitive. <%@ Control EnableViewState="false" Inherits="MyPortal.Profiles.LogInControl" %> <asp:Substitution runat="server" MethodName="ShowLogInBox" /> But code is a little bit tricky. Based on current user instance we decide which login control to load. Then we create page instance and load our control through it. When control is loaded we will call DataBind() method. In this method we evaluate all fields in loaded control (it was best choice as Load and other events will not be fired). Take a look at the code. public static string ShowLogInBox(HttpContext context) {     var user = SPContext.Current.Web.CurrentUser;     string controlName;       if (user != null)         controlName = "AuthenticatedLogInControl.ascx";     else         controlName = "AnonymousLogInControl.ascx";       var path = "~/_controltemplates/" + controlName;     var output = new StringBuilder(10000);       using(var page = new Page())     using(var ctl = page.LoadControl(path))     using(var writer = new StringWriter(output))     using(var htmlWriter = new HtmlTextWriter(writer))     {         ctl.DataBind();         ctl.RenderControl(htmlWriter);     }     return output.ToString(); } When control is bound to data we ask to render it its contents to StringBuilder. Now we have the output of control as string and we can return it from our method. Of course, notice how correct I am with resources disposing. :) The method that returns contents for substitution control is static method that has no connection with control instance because hen page is read from cache there are no instances of controls available. Conclusion As you saw it was not very hard to use donut caching with user controls. Instead of writing mark-up of controls to static method that is bound to substitution control we can still use our user controls.

  Read the article

• SQL SERVER – SQL in Sixty Seconds – 5 Videos from Joes 2 Pros Series – SQL Exam Prep Series 70-433

  - by pinaldave

  Joes 2 Pros SQL Server Learning series is indeed fun. Joes 2 Pros series is written for beginners and who wants to build expertise for SQL Server programming and development from fundamental. In the beginning of the series author Rick Morelan is not shy to explain the simplest concept of how to open SQL Server Management Studio. Honestly the book starts with that much basic but as it progresses further Rick discussing about various advanced concepts from query tuning to Core Architecture. This five part series is written with keeping SQL Server Exam 70-433. Instead of just focusing on what will be there in exam, this series is focusing on learning the important concepts thoroughly. This book no way take short cut to explain any concepts and at times, will go beyond the topic at length. The best part is that all the books has many companion videos explaining the concepts and videos. Every Wednesday I like to post a video which explains something in quick few seconds. Today we will go over five videos which I posted in my earlier posts related to Joes 2 Pros series. Introduction to XML Data Type Methods – SQL in Sixty Seconds #015 The XML data type was first introduced with SQL Server 2005. This data type continues with SQL Server 2008 where expanded XML features are available, most notably is the power of the XQuery language to analyze and query the values contained in your XML instance. There are five XML data type methods available in SQL Server 2008: query() – Used to extract XML fragments from an XML data type. value() – Used to extract a single value from an XML document. exist() – Used to determine if a specified node exists. Returns 1 if yes and 0 if no. modify() – Updates XML data in an XML data type. node() – Shreds XML data into multiple rows (not covered in this blog post). [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Error Actions – SQL in Sixty Seconds #014 Most people believe that when SQL Server encounters an error severity level 11 or higher the remaining SQL statements will not get executed. In addition, people also believe that if any error severity level of 11 or higher is hit inside an explicit transaction, then the whole statement will fail as a unit. While both of these beliefs are true 99% of the time, they are not true in all cases. It is these outlying cases that frequently cause unexpected results in your SQL code. To understand how to achieve consistent results you need to know the four ways SQL Error Actions can react to error severity levels 11-16: Statement Termination – The statement with the procedure fails but the code keeps on running to the next statement. Transactions are not affected. Scope Abortion – The current procedure, function or batch is aborted and the next calling scope keeps running. That is, if Stored Procedure A calls B and C, and B fails, then nothing in B runs but A continues to call C. @@Error is set but the procedure does not have a return value. Batch Termination – The entire client call is terminated. XACT_ABORT – (ON = The entire client call is terminated.) or (OFF = SQL Server will choose how to handle all errors.) [Detailed Blog Post] | [Quiz with Answer] Introduction to Basics of a Query Hint – SQL in Sixty Seconds #013 Query hints specify that the indicated hints should be used throughout the query. Query hints affect all operators in the statement and are implemented using the OPTION clause. Cautionary Note: Because the SQL Server Query Optimizer typically selects the best execution plan for a query, it is highly recommended that hints be used as a last resort for experienced developers and database administrators to achieve the desired results. [Detailed Blog Post] | [Quiz with Answer] Introduction to Hierarchical Query – SQL in Sixty Seconds #012 A CTE can be thought of as a temporary result set and are similar to a derived table in that it is not stored as an object and lasts only for the duration of the query. A CTE is generally considered to be more readable than a derived table and does not require the extra effort of declaring a Temp Table while providing the same benefits to the user. However; a CTE is more powerful than a derived table as it can also be self-referencing, or even referenced multiple times in the same query. A recursive CTE requires four elements in order to work properly: Anchor query (runs once and the results ‘seed’ the Recursive query) Recursive query (runs multiple times and is the criteria for the remaining results) UNION ALL statement to bind the Anchor and Recursive queries together. INNER JOIN statement to bind the Recursive query to the results of the CTE. [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Server Security – SQL in Sixty Seconds #011 Let’s get some basic definitions down first. Take the workplace example where “Tom” needs “Read” access to the “Financial Folder”. What are the Securable, Principal, and Permissions from that last sentence? A Securable is a resource that someone might want to access (like the Financial Folder). A Principal is anything that might want to gain access to the securable (like Tom). A Permission is the level of access a principal has to a securable (like Read). [Detailed Blog Post] | [Quiz with Answer] Please leave a comment explain which one was your favorite video as that will help me understand what works and what needs improvement. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology, Video

  Read the article

• ASP.NET WebAPI Security 2: Identity Architecture

  - by Your DisplayName here!

  Pedro has beaten me to the punch with a detailed post (and diagram) about the WebAPI hosting architecture. So go read his post first, then come back so we can have a closer look at what that means for security. The first important takeaway is that WebAPI is hosting independent-  currently it ships with two host integration implementations – one for ASP.NET (aka web host) and WCF (aka self host). Pedro nicely shows the integration into the web host. Self hosting is not done yet so we will mainly focus on the web hosting case and I will point out security related differences when they exist. The interesting part for security (amongst other things of course) is the HttpControllerHandler (see Pedro’s diagram) – this is where the host specific representation of an HTTP request gets converted to the WebAPI abstraction (called HttpRequestMessage). The ConvertRequest method does the following: Create a new HttpRequestMessage. Copy URI, method and headers from the HttpContext. Copies HttpContext.User to the Properties<string, object> dictionary on the HttpRequestMessage. The key used for that can be found on HttpPropertyKeys.UserPrincipalKey (which resolves to “MS_UserPrincipal”). So the consequence is that WebAPI receives whatever IPrincipal has been set by the ASP.NET pipeline (in the web hosting case). Common questions are: Are there situations where is property does not get set? Not in ASP.NET – the DefaultAuthenticationModule in the HTTP pipeline makes sure HttpContext.User (and Thread.CurrentPrincipal – more on that later) are always set. Either to some authenticated user – or to an anonymous principal. This may be different in other hosting environments (again more on that later). Why so generic? Keep in mind that WebAPI is hosting independent and may run on a host that materializes identity completely different compared to ASP.NET (or .NET in general). This gives them a way to evolve the system in the future. How does WebAPI code retrieve the current client identity? HttpRequestMessage has an extension method called GetUserPrincipal() which returns the property as an IPrincipal. A quick look at self hosting shows that the moral equivalent of HttpControllerHandler.ConvertRequest() is HttpSelfHostServer.ProcessRequestContext(). Here the principal property gets only set when the host is configured for Windows authentication (inconsisteny). Do I like that? Well – yes and no. Here are my thoughts: I like that it is very straightforward to let WebAPI inherit the client identity context of the host. This might not always be what you want – think of an ASP.NET app that consists of UI and APIs – the UI might use Forms authentication, the APIs token based authentication. So it would be good if the two parts would live in a separate security world. It makes total sense to have this generic hand off point for identity between the host and WebAPI. It also makes total sense for WebAPI plumbing code (especially handlers) to use the WebAPI specific identity abstraction. But – c’mon we are running on .NET. And the way .NET represents identity is via IPrincipal/IIdentity. That’s what every .NET developer on this planet is used to. So I would like to see a User property of type IPrincipal on ApiController. I don’t like the fact that Thread.CurrentPrincipal is not populated. T.CP is a well established pattern as a one stop shop to retrieve client identity on .NET.  That makes a lot of sense – even if the name is misleading at best. There might be existing library code you want to call from WebAPI that makes use of T.CP (e.g. PrincipalPermission, or a simple .Name or .IsInRole()). Having the client identity as an ambient property is useful for code that does not have access to the current HTTP request (for calling GetUserPrincipal()). I don’t like the fact that that the client identity conversion from host to WebAPI is inconsistent. This makes writing security plumbing code harder. I think the logic should always be: If the host has a client identity representation, copy it. If not, set an anonymous principal on the request message. Btw – please don’t annoy me with the “but T.CP is static, and static is bad for testing” chant. T.CP is a getter/setter and, in fact I find it beneficial to be able to set different security contexts in unit tests before calling in some logic. And, in case you have wondered – T.CP is indeed thread static (and the name comes from a time where a logical operation was bound to a thread – which is not true anymore). But all thread creation APIs in .NET actually copy T.CP to the new thread they create. This is the case since .NET 2.0 and is certainly an improvement compared to how Win32 does things. So to sum it up: The host plumbing copies the host client identity to WebAPI (this is not perfect yet, but will surely be improved). or in other words: The current WebAPI bits don’t ship with any authentication plumbing, but solely use whatever authentication (and thus client identity) is set up by the host. WebAPI developers can retrieve the client identity from the HttpRequestMessage. Hopefully my proposed changes around T.CP and the User property on ApiController will be added. In the next post, I will detail how to add WebAPI specific authentication support, e.g. for Basic Authentication and tokens. This includes integrating the notion of claims based identity. After that we will look at the built-in authorization bits and how to improve them as well. Stay tuned.

  Read the article

• Windows 7 doesn't boot after Ubuntu install

  - by Omu

  I had windows 7 installed on my pc, then I installed Ubuntu 10.10/ During the installation process I have chosen to manually set my partitions: I set a 10GB drive for ubuntu root 1GB drive for swap and for boot drive I've chosen the one used by windows 7 Now I can boot ubuntu, I have the windows 7 option in the boot list, but when I choose Windows 7, it shows me a black screen for a second and returns back to boot screen. Boot Info Script 0.55 dated February 15th, 2010 ============================= Boot Info Summary: ============================== = Windows is installed in the MBR of /dev/sda sda1: _________________________________________________________________________ File system: ntfs Boot sector type: Grub 2 Boot sector info: Grub 2 is installed in the boot sector of sda1 and looks at sector 304908237 of the same hard drive for core.img, but core.img can not be found at this location. No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files/dirs: /bootmgr /Boot/BCD /Windows/System32/winload.exe sda2: _________________________________________________________________________ File system: ntfs Boot sector type: Windows XP Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files/dirs: sda3: _________________________________________________________________________ File system: Extended Partition Boot sector type: - Boot sector info: sda5: _________________________________________________________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Ubuntu 10.10 Boot files/dirs: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img sda4: _________________________________________________________________________ File system: swap Boot sector type: - Boot sector info: =========================== Drive/Partition Info: ============================= Drive: sda ___________________ _____________________________________________________ Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start End Size Id System /dev/sda1 * 63 62,894,474 62,894,412 7 HPFS/NTFS /dev/sda2 62,894,478 291,579,749 228,685,272 7 HPFS/NTFS /dev/sda3 291,579,811 309,157,937 17,578,127 5 Extended /dev/sda5 291,579,813 309,157,937 17,578,125 83 Linux /dev/sda4 309,159,936 312,580,095 3,420,160 82 Linux swap / Solaris blkid -c /dev/null: ____________________________________________________________ Device UUID TYPE LABEL /dev/sda1 1266BB2766BB0A8D ntfs /dev/sda2 BEDBF1147C76F703 ntfs DATA /dev/sda3: PTTYPE="dos" /dev/sda4 dd38226d-c7c9-4ae5-a726-6d18d34a22e4 swap /dev/sda5 e1dafd1c-f855-406b-8f9a-f9d527c70255 ext4 /dev/sda: PTTYPE="dos" ============================ "mount | grep ^/dev output: =========================== Device Mount_Point Type Options /dev/sda5 / ext4 (rw,errors=remount-ro,commit=0) =========================== sda5/boot/grub/grub.cfg: =========================== # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga } insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=640x480 load_video insmod gfxterm fi terminal_output gfxterm insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 set locale_dir=($root)/boot/grub/locale set lang=en insmod gettext if [ "${recordfail}" = 1 ]; then set timeout=-1 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 linux /boot/vmlinuz-2.6.35-22-generic root=UUID=e1dafd1c-f855-406b-8f9a-f9d527c70255 ro quiet splash initrd /boot/initrd.img-2.6.35-22-generic } menuentry 'Ubuntu, with Linux 2.6.35-22-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 echo 'Loading Linux 2.6.35-22-generic ...' linux /boot/vmlinuz-2.6.35-22-generic root=UUID=e1dafd1c-f855-406b-8f9a-f9d527c70255 ro single echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-2.6.35-22-generic } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set e1dafd1c-f855-406b-8f9a-f9d527c70255 linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### menuentry "Windows 7 (loader) (on /dev/sda1)" { insmod part_msdos insmod ntfs set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set 1266bb2766bb0a8d chainloader +1 } ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ### =============================== sda5/etc/fstab: =============================== # /etc/fstab: static file system information. # # Use 'blkid -o value -s UUID' to print the universally unique identifier # for a device; this may be used with UUID= as a more robust way to name # devices that works even if disks are added and removed. See fstab(5). # # proc /proc proc nodev,noexec,nosuid 0 0 /dev/sda5 / ext4 errors=remount-ro 0 1 # swap was on /dev/sda4 during installation UUID=dd38226d-c7c9-4ae5-a726-6d18d34a22e4 none swap sw 0 0 =================== sda5: Location of files loaded by Grub: =================== 156.1GB: boot/grub/core.img 156.3GB: boot/grub/grub.cfg 149.9GB: boot/initrd.img-2.6.35-22-generic 156.3GB: boot/vmlinuz-2.6.35-22-generic 149.9GB: initrd.img 156.3GB: vmlinuz

  Read the article

• Token based Authentication for WCF HTTP/REST Services: Authentication

  - by Your DisplayName here!

  This post shows some of the implementation techniques for adding token and claims based security to HTTP/REST services written with WCF. For the theoretical background, see my previous post. Disclaimer The framework I am using/building here is not the only possible approach to tackle the problem. Based on customer feedback and requirements the code has gone through several iterations to a point where we think it is ready to handle most of the situations. Goals and requirements The framework should be able to handle typical scenarios like username/password based authentication, as well as token based authentication The framework should allow adding new supported token types Should work with WCF web programming model either self-host or IIS hosted Service code can rely on an IClaimsPrincipal on Thread.CurrentPrincipal that describes the client using claims-based identity Implementation overview In WCF the main extensibility point for this kind of security work is the ServiceAuthorizationManager. It gets invoked early enough in the pipeline, has access to the HTTP protocol details of the incoming request and can set Thread.CurrentPrincipal. The job of the SAM is simple: Check the Authorization header of the incoming HTTP request Check if a “registered” token (more on that later) is present If yes, validate the token using a security token handler, create the claims principal (including claims transformation) and set Thread.CurrentPrincipal If no, set an anonymous principal on Thread.CurrentPrincipal. By default, anonymous principals are denied access – so the request ends here with a 401 (more on that later). To wire up the custom authorization manager you need a custom service host – which in turn needs a custom service host factory. The full object model looks like this: Token handling A nice piece of existing WIF infrastructure are security token handlers. Their job is to serialize a received security token into a CLR representation, validate the token and turn the token into claims. The way this works with WS-Security based services is that WIF passes the name/namespace of the incoming token to WIF’s security token handler collection. This in turn finds out which token handler can deal with the token and returns the right instances. For HTTP based services we can do something very similar. The scheme on the Authorization header gives the service a hint how to deal with an incoming token. So the only missing link is a way to associate a token handler (or multiple token handlers) with a scheme and we are (almost) done. WIF already includes token handler for a variety of tokens like username/password or SAML 1.1/2.0. The accompanying sample has a implementation for a Simple Web Token (SWT) token handler, and as soon as JSON Web Token are ready, simply adding a corresponding token handler will add support for this token type, too. All supported schemes/token types are organized in a WebSecurityTokenHandlerCollectionManager and passed into the host factory/host/authorization manager. Adding support for basic authentication against a membership provider would e.g. look like this (in global.asax): var manager = new WebSecurityTokenHandlerCollectionManager(); manager.AddBasicAuthenticationHandler((username, password) => Membership.ValidateUser(username, password));   Adding support for Simple Web Tokens with a scheme of Bearer (the current OAuth2 scheme) requires passing in a issuer, audience and signature verification key: manager.AddSimpleWebTokenHandler(     "Bearer",     "http://identityserver.thinktecture.com/trust/initial",     "https://roadie/webservicesecurity/rest/",     "WFD7i8XRHsrUPEdwSisdHoHy08W3lM16Bk6SCT8ht6A="); In some situations, SAML token may be used as well. The following configures SAML support for a token coming from ADFS2: var registry = new ConfigurationBasedIssuerNameRegistry(); registry.AddTrustedIssuer( "d1 c5 b1 25 97 d0 36 94 65 1c e2 64 fe 48 06 01 35 f7 bd db", "ADFS"); var adfsConfig = new SecurityTokenHandlerConfiguration(); adfsConfig.AudienceRestriction.AllowedAudienceUris.Add( new Uri("https://roadie/webservicesecurity/rest/")); adfsConfig.IssuerNameRegistry = registry; adfsConfig.CertificateValidator = X509CertificateValidator.None; // token decryption (read from config) adfsConfig.ServiceTokenResolver = IdentityModelConfiguration.ServiceConfiguration.CreateAggregateTokenResolver();             manager.AddSaml11SecurityTokenHandler("SAML", adfsConfig);   Transformation The custom authorization manager will also try to invoke a configured claims authentication manager. This means that the standard WIF claims transformation logic can be used here as well. And even better, can be also shared with e.g. a “surrounding” web application. Error handling A WCF error handler takes care of turning “access denied” faults into 401 status codes and a message inspector adds the registered authentication schemes to the outgoing WWW-Authenticate header when a 401 occurs. The next post will conclude with authorization as well as the source code download.   (Wanna learn more about federation, WIF, claims, tokens etc.? Click here.)

  Read the article

• Making your WCF Web Apis to speak in multiple languages

  - by cibrax

  One of the key aspects of how the web works today is content negotiation. The idea of content negotiation is based on the fact that a single resource can have multiple representations, so user agents (or clients) and servers can work together to chose one of them. The http specification defines several “Accept” headers that a client can use to negotiate content with a server, and among all those, there is one for restricting the set of natural languages that are preferred as a response to a request, “Accept-Language”. For example, a client can specify “es” in this header for specifying that he prefers to receive the content in spanish or “en” in english. However, there are certain scenarios where the “Accept-Language” header is just not enough, and you might want to have a way to pass the “accepted” language as part of the resource url as an extension. For example, http://localhost/ProductCatalog/Products/1.es” returns all the descriptions for the product with id “1” in spanish. This is useful for scenarios in which you want to embed the link somewhere, such a document, an email or a page.  Supporting both scenarios, the header and the url extension, is really simple in the new WCF programming model. You only need to provide a processor implementation for any of them. Let’s say I have a resource implementation as part of a product catalog I want to expose with the WCF web apis. [ServiceContract][Export]public class ProductResource{ IProductRepository repository;  [ImportingConstructor] public ProductResource(IProductRepository repository) { this.repository = repository; }  [WebGet(UriTemplate = "{id}")] public Product Get(string id, HttpResponseMessage response) { var product = repository.GetById(int.Parse(id)); if (product == null) { response.StatusCode = HttpStatusCode.NotFound; response.Content = new StringContent(Messages.OrderNotFound); }  return product; }} The Get method implementation in this resource assumes the desired culture will be attached to the current thread (Thread.CurrentThread.Culture). Another option is to pass the desired culture as an additional argument in the method, so my processor implementation will handle both options. This method is also using an auto-generated class for handling string resources, Messages, which is available in the different cultures that the service implementation supports. For example, Messages.resx contains “OrderNotFound”: “Order Not Found” Messages.es.resx contains “OrderNotFound”: “No se encontro orden” The processor implementation bellow tackles the first scenario, in which the desired language is passed as part of the “Accept-Language” header. public class CultureProcessor : Processor<HttpRequestMessage, CultureInfo>{ string defaultLanguage = null;  public CultureProcessor(string defaultLanguage = "en") { this.defaultLanguage = defaultLanguage; this.InArguments[0].Name = HttpPipelineFormatter.ArgumentHttpRequestMessage; this.OutArguments[0].Name = "culture"; }  public override ProcessorResult<CultureInfo> OnExecute(HttpRequestMessage request) { CultureInfo culture = null; if (request.Headers.AcceptLanguage.Count > 0) { var language = request.Headers.AcceptLanguage.First().Value; culture = new CultureInfo(language); } else { culture = new CultureInfo(defaultLanguage); }  Thread.CurrentThread.CurrentCulture = culture; Messages.Culture = culture;  return new ProcessorResult<CultureInfo> { Output = culture }; }}   As you can see, the processor initializes a new CultureInfo instance with the value provided in the “Accept-Language” header, and set that instance to the current thread and the auto-generated resource class with all the messages. In addition, the CultureInfo instance is returned as an output argument called “culture”, making possible to receive that argument in any method implementation   The following code shows the implementation of the processor for handling languages as url extensions.   public class CultureExtensionProcessor : Processor<HttpRequestMessage, Uri>{ public CultureExtensionProcessor() { this.OutArguments[0].Name = HttpPipelineFormatter.ArgumentUri; }  public override ProcessorResult<Uri> OnExecute(HttpRequestMessage httpRequestMessage) { var requestUri = httpRequestMessage.RequestUri.OriginalString;  var extensionPosition = requestUri.LastIndexOf(".");  if (extensionPosition > -1) { var extension = requestUri.Substring(extensionPosition + 1);  var query = httpRequestMessage.RequestUri.Query;  requestUri = string.Format("{0}?{1}", requestUri.Substring(0, extensionPosition), query); ;  var uri = new Uri(requestUri);  httpRequestMessage.Headers.AcceptLanguage.Clear();  httpRequestMessage.Headers.AcceptLanguage.Add(new StringWithQualityHeaderValue(extension));  var result = new ProcessorResult<Uri>();  result.Output = uri;  return result; }  return new ProcessorResult<Uri>(); }} The last step is to inject both processors as part of the service configuration as it is shown bellow, public void RegisterRequestProcessorsForOperation(HttpOperationDescription operation, IList<Processor> processors, MediaTypeProcessorMode mode){ processors.Insert(0, new CultureExtensionProcessor()); processors.Add(new CultureProcessor());} Once you configured the two processors in the pipeline, your service will start speaking different languages :). Note: Url extensions don’t seem to be working in the current bits when you are using Url extensions in a base address. As far as I could see, ASP.NET intercepts the request first and tries to route the request to a registered ASP.NET Http Handler with that extension. For example, “http://localhost/ProductCatalog/products.es” does not work, but “http://localhost/ProductCatalog/products/1.es” does.

  Read the article

• Dynamically switching the theme in Orchard

  - by Bertrand Le Roy

  It may sound a little puzzling at first, but in Orchard CMS, more than one theme can be active at any given time. The reason for that is that we have an extensibility point that allows a module (or a theme) to participate in the choice of the theme to use, for each request. The motivation for building the theme engine this way was to enable developers to switch themes based on arbitrary criteria, such as user preferences or the user agent (if you want to serve a mobile theme for phones for example). The choice is made between the active themes, which is why there is a difference between the default theme and the active themes. In order to have a say in the choice of the theme, all you have to do is implement IThemeSelector. That interface is quite simple as it only has one method, GetTheme, that takes the current RequestContext and returns a ThemeSelectorResult or null if the implementation of the interface does not want to participate in the current request (we'll see an example in a moment). ThemeSelectorResult itself is just a ThemeName string property and an integer Priority. We're using a priority so that an arbitrary number of implementations of IThemeSelector can contribute to the choice of a theme. If you look for existing implementations of the interface in Orchard, you'll find four: AdminThemeSelector: selects the TheAdmin theme with a very high priority (100) if the current request is for a page that is part of the admin. Otherwise, null is returned, which enables other implementations to choose the theme. PreviewThemeSelector: selects the preview theme if there is one, with a high priority (90), and null otherwise. This enables administrators to view the site under a different theme while everybody else continues to see the current default theme. SiteThemeSelector: this is the implementation that is doing what you expect most of the time, which is to get the current theme from site settings and set it with a priority of –5. SafeModeThemeSelector: this is the fallback implementation, which should almost never win. It sets the theme as the safe mode theme, which has no style and just uses the default templates for everything. The priority is very low (-100). While this extensibility mechanism is great to have, I wanted to bring that level of choice into the hands of the site administrator rather than just developers. In order to achieve that, I built the Vandelay Theme Picker module. The module provides administration UI to create rules for theme selection. It provides its own extensibility point (the IThemeSelectionRule interface) and one implementation of a rule: UserAgentThemeSelectorRule. This rule gets the current user agent from the context and tries to match it with a regular expression that the administrator can configure in the admin UI. You can for example configure a rule with a regular expression that matches IE6 and serve a different subtheme where the stylesheet has been tweaked for such an antique browser. Another possible configuration is to detect mobile devices from their agent string and serve the mobile theme. All those operations can be done with this module entirely from the admin UI, without writing a line of code. The module also offers the administrator the opportunity to inject a link into the front-end in a specific zone and with a specific position that enables the user to switch to the default theme if he wishes to. This is especially useful for sites that use a mobile theme but still want to allow users to use the full desktop site. While the module is nice and flexible, it may be overkill. On my own personal blog, I have only two active themes: the desktop theme and the mobile theme. I'm fine with going into code to change the criteria on which to switch the theme, so I'm not using my own Theme Picker module. Instead, I made the mobile theme a theme with code (in other words there is a csproj file in the theme). The project includes a single C# file, my MobileThemeSelector for which the code is the following: public class MobileThemeSelector : IThemeSelector { private static readonly Regex _Msie678 = new Regex(@"^Mozilla\/4\.0 \(compatible; MSIE [678]" + @"\.0; Windows NT \d\.\d(.*)\)$", RegexOptions.IgnoreCase); private ThemeSelectorResult _requestCache; private bool _requestCached; public ThemeSelectorResult GetTheme(RequestContext context) { if (_requestCached) return _requestCache; _requestCached = true; var userAgent = context.HttpContext.Request.UserAgent; if (userAgent.IndexOf("phone", StringComparison.OrdinalIgnoreCase) != -1 || _Msie678.IsMatch(userAgent) || userAgent.IndexOf("windows live writer", StringComparison.OrdinalIgnoreCase) != -1) { _requestCache = new ThemeSelectorResult { Priority = 10, ThemeName = "VuLuMobile" }; } return _requestCache; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The theme selector selects the current theme for Internet Explorer versions 6 to 8, for phones, and for Windows Live Writer (so that the theme that is used when I write posts is as simple as possible). What's interesting here is that it's the theme that selects itself here, based on its own criteria. This should give you a good panorama of what's possible in terms of dynamic theme selection in Orchard. I hope you find some fun uses for it. As usual, I can't wait to see what you're going to come up with…

  Read the article

• How to Secure a Data Role by Multiple Business Units

  - by Elie Wazen

  In this post we will see how a Role can be data secured by multiple Business Units (BUs).  Separate Data Roles are generally created for each BU if a corresponding data template generates roles on the basis of the BU dimension. The advantage of creating a policy with a rule that includes multiple BUs is that while mapping these roles in HCM Role Provisioning Rules, fewer number of entires need to be made. This could facilitate maintenance for enterprises with a large number of Business Units. Note: The example below applies as well if the securing entity is Inventory Organization. Let us take for example the case of a user provisioned with the "Accounts Payable Manager - Vision Operations" Data Role in Fusion Applications. This user will be able to access Invoices in Vision Operations but will not be able to see Invoices in Vision Germany. Figure 1. A User with a Data Role restricting them to Data from BU: Vision Operations With the role granted above, this is what the user will see when they attempt to select Business Units while searching for AP Invoices. Figure 2.The List Of Values of Business Units is limited to single one. This is the effect of the Data Role granted to that user as can be seen in Figure 1 In order to create a data role that secures by multiple BUs,  we need to start by creating a condition that groups those Business Units we want to include in that data role. This is accomplished by creating a new condition against the BU View .  That Condition will later be used to create a data policy for our newly created Role.  The BU View is a Database resource and  is accessed from APM as seen in the search below Figure 3.Viewing a Database Resource in APM The next step is create a new condition,  in which we define a sql predicate that includes 2 BUs ( The ids below refer to Vision Operations and Vision Germany).  At this point we have simply created a standalone condition.  We have not used this condition yet, and security is therefore not affected. Figure 4. Custom Role that inherits the Purchase Order Overview Duty We are now ready to create our Data Policy.  in APM, we search for our newly Created Role and Navigate to “Find Global Policies”.  we query the Role we want to secure and navigate to view its global policies. Figure 5. The Job Role we plan on securing We can see that the role was not defined with a Data Policy . So will create one that uses the condition we created earlier.   Figure 6. Creating a New Data Policy In the General Information tab, we have to specify the DB Resource that the Security Policy applies to:  In our case this is the BU View Figure 7. Data Policy Definition - Selection of the DB Resource we will secure by In the Rules Tab, we  make the rule applicable to multiple values of the DB Resource we selected in the previous tab.  This is where we associate the condition we created against the BU view to this data policy by entering the Condition name in the Condition field Figure 8. Data Policy Rule The last step of Defining the Data Policy, consists of  explicitly selecting  the Actions that are goverened by this Data Policy.  In this case for example we select the Actions displayed below in the right pane. Once the record is saved , we are ready to use our newly secured Data Role. Figure 9. Data Policy Actions We can now see a new Data Policy associated with our Role.  Figure 10. Role is now secured by a Data Policy We now Assign that new Role to the User.  Of course this does not have to be done in OIM and can be done using a Provisioning Rule in HCM. Figure 11. Role assigned to the User who previously was granted the Vision Ops secured role. Once that user accesses the Invoices Workarea this is what they see: In the image below the LOV of Business Unit returns the two values defined in our data policy namely: Vision Operations and Vision Germany Figure 12. The List Of Values of Business Units now includes the two we included in our data policy. This is the effect of the data role granted to that user as can be seen in Figure 11

  Read the article

• Subterranean IL: Constructor constraints

  - by Simon Cooper

  The constructor generic constraint is a slightly wierd one. The ECMA specification simply states that it: constrains [the type] to being a concrete reference type (i.e., not abstract) that has a public constructor taking no arguments (the default constructor), or to being a value type. There seems to be no reference within the spec to how you actually create an instance of a generic type with such a constraint. In non-generic methods, the normal way of creating an instance of a class is quite different to initializing an instance of a value type. For a reference type, you use newobj: newobj instance void IncrementableClass::.ctor() and for value types, you need to use initobj: .locals init ( valuetype IncrementableStruct s1 ) ldloca 0 initobj IncrementableStruct But, for a generic method, we need a consistent method that would work equally well for reference or value types. Activator.CreateInstance<T> To solve this problem the CLR designers could have chosen to create something similar to the constrained. prefix; if T is a value type, call initobj, and if it is a reference type, call newobj instance void !!0::.ctor(). However, this solution is much more heavyweight than constrained callvirt. The newobj call is encoded in the assembly using a simple reference to a row in a metadata table. This encoding is no longer valid for a call to !!0::.ctor(), as different constructor methods occupy different rows in the metadata tables. Furthermore, constructors aren't virtual, so we would have to somehow do a dynamic lookup to the correct method at runtime without using a MethodTable, something which is completely new to the CLR. Trying to do this in IL results in the following verification error: newobj instance void !!0::.ctor() [IL]: Error: Unable to resolve token. This is where Activator.CreateInstance<T> comes in. We can call this method to return us a new T, and make the whole issue Somebody Else's Problem. CreateInstance does all the dynamic method lookup for us, and returns us a new instance of the correct reference or value type (strangely enough, Activator.CreateInstance<T> does not itself have a .ctor constraint on its generic parameter): .method private static !!0 CreateInstance<.ctor T>() { call !!0 [mscorlib]System.Activator::CreateInstance<!!0>() ret } Going further: compiler enhancements Although this method works perfectly well for solving the problem, the C# compiler goes one step further. If you decompile the C# version of the CreateInstance method above: private static T CreateInstance() where T : new() { return new T(); } what you actually get is this (edited slightly for space & clarity): .method private static !!T CreateInstance<.ctor T>() { .locals init ( [0] !!T CS$0$0000, [1] !!T CS$0$0001 ) DetectValueType: ldloca.s 0 initobj !!T ldloc.0 box !!T brfalse.s CreateInstance CreateValueType: ldloca.s 1 initobj !!T ldloc.1 ret CreateInstance: call !!0 [mscorlib]System.Activator::CreateInstance<T>() ret } What on earth is going on here? Looking closer, it's actually quite a clever performance optimization around value types. So, lets dissect this code to see what it does. The CreateValueType and CreateInstance sections should be fairly self-explanatory; using initobj for value types, and Activator.CreateInstance for reference types. How does the DetectValueType section work? First, the stack transition for value types: ldloca.s 0 // &[!!T(uninitialized)] initobj !!T // ldloc.0 // !!T box !!T // O[!!T] brfalse.s // branch not taken When the brfalse.s is hit, the top stack entry is a non-null reference to a boxed !!T, so execution continues to to the CreateValueType section. What about when !!T is a reference type? Remember, the 'default' value of an object reference (type O) is zero, or null. ldloca.s 0 // &[!!T(null)] initobj !!T // ldloc.0 // null box !!T // null brfalse.s // branch taken Because box on a reference type is a no-op, the top of the stack at the brfalse.s is null, and so the branch to CreateInstance is taken. For reference types, Activator.CreateInstance is called which does the full dynamic lookup using reflection. For value types, a simple initobj is called, which is far faster, and also eliminates the unboxing that Activator.CreateInstance has to perform for value types. However, this is strictly a performance optimization; Activator.CreateInstance<T> works for value types as well as reference types. Next... That concludes the initial premise of the Subterranean IL series; to cover the details of generic methods and generic code in IL. I've got a few other ideas about where to go next; however, if anyone has any itching questions, suggestions, or things you've always wondered about IL, do let me know.

  Read the article

• Execute TSQL statement with ExecuteStoreQuery in entity framework 4.0

  - by Jalpesh P. Vadgama

  I was playing with entity framework in recent days and I was searching something that how we can execute TSQL statement in entity framework. And I have found one great way to do that with entity framework ‘ExecuteStoreQuery’ method. It’s executes a TSQL statement against data source given enity framework context and returns strongly typed result. You can find more information about ExcuteStoreQuery from following link. http://msdn.microsoft.com/en-us/library/dd487208.aspx So let’s examine how it works. So Let’s first create a table against which we are going to execute TSQL statement. So I have added a SQL Express database as following. Now once we are done with adding a database let’s add a table called Client like following. Here you can see above Client table is very simple. There are only two fields ClientId and ClientName where ClientId is primary key and ClientName is field where we are going to store client name. Now it’s time to add some data to the table. So I have added some test data like following. Now it’s time to add entity framework model class. So right click project->Add new item and select ADO.NET entity model as following. After clicking on add button a wizard will start it will ask whether we need to create model classes from database or not but we already have our client table ready so I have selected generate from database as following. Once you process further in wizard it will be presented a screen where we can select the our table like following. Now once you click finish it will create model classes with for us. Now we need a gridview control where we need to display those data. So in Default.aspx page I have added a grid control like following. <%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="EntityFramework._Default" %> <asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent"> </asp:Content> <asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent"> <h2> Welcome to ASP.NET! </h2> <p> To learn more about ASP.NET visit <a href="http://www.asp.net" title="ASP.NET Website">www.asp.net</a>. </p> <p> You can also find <a href="http://go.microsoft.com/fwlink/?LinkID=152368&amp;clcid=0x409" title="MSDN ASP.NET Docs">documentation on ASP.NET at MSDN</a>. <asp:GridView ID="grdClient" runat="server"> </asp:GridView> </p> </asp:Content> Now once we are done with adding Gridview its time to write code for server side. So I have written following code in Page_load event of default.aspx page. protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { using (var context = new EntityFramework.TestEntities()) { ObjectResult<Client> result = context.ExecuteStoreQuery<Client>("Select * from Client"); grdClient.DataSource = result; grdClient.DataBind(); } } } Here in the above code you can see that I have written create a object of our entity model and then with the help of the ExecuteStoreQuery method I have execute a simple select TSQL statement which will return a object result. I have bind that object result with gridview to display data. So now we are done with coding.So let’s run application in browser. Following is output as expected. That’s it. Hope you like it. Stay tuned for more..Till then happy programming.

  Read the article

• A Semantic Model For Html: TagBuilder and HtmlTags

  - by Ryan Ohs

  In this post I look into the code smell that is HTML literals and show how we can refactor these pesky strings into a friendlier and more maintainable model.   The Problem When I started writing MVC applications, I quickly realized that I built a lot of my HTML inside HtmlHelpers. As I did this, I ended up moving quite a bit of HTML into string literals inside my helper classes. As I wanted to add more attributes (such as classes) to my tags, I needed to keep adding overloads to my helpers. A good example of this end result is the default html helpers that come with the MVC framework. Too many overloads make me crazy! The problem with all these overloads is that they quickly muck up the API and nobody can remember exactly what order the parameters go in. I've seen many presenters (including members of the ASP.NET MVC team!) stumble before realizing that their view wasn't compiling because they needed one more null parameter in the call to Html.ActionLink(). What if instead of writing Html.ActionLink("Edit", "Edit", null, new { @class = "navigation" }) we could do Html.LinkToAction("Edit").Text("Edit").AddClass("navigation") ? Wouldn't that be much easier to remember and understand?  We can do this if we introduce a semantic model for building our HTML.   What is a Semantic Model? According to Martin Folwer, "a semantic model is an in-memory representation, usually an object model, of the same subject that the domain specific language describes." In our case, the model would be a set of classes that know how to render HTML. By using a semantic model we can free ourselves from dealing with strings and instead output the HTML (typically via ToString()) once we've added all the elements and attributes we desire to the model. There are two primary semantic models available in ASP.NET MVC: MVC 2.0's TagBuilder and FubuMVC's HtmlTags.   TagBuilder TagBuilder is the html builder that is available in ASP.NET MVC 2.0. I'm not a huge fan but it gets the job done -- for simple jobs.  Here's an overview of how to use TagBuilder. See my Tips section below for a few comments on that example. The disadvantage of TagBuilder is that unless you wrap it up with our own classes, you still have to write the actual tag name over and over in your code. eg. new TagBuilder("div") instead of new DivTag(). I also think it's method names are a little too long. Why not have AddClass() instead of AddCssClass() or Text() instead of SetInnerText()? What those methods are doing should be pretty obvious even in the short form. I also don't like that it wants to generate an id attribute from your input instead of letting you set it yourself using external conventions. (See GenerateId() and IdAttributeDotReplacement)). Obviously these come from Microsoft's default approach to MVC but may not be optimal for all programmers.   HtmlTags HtmlTags is in my opinion the much better option for generating html in ASP.NET MVC. It was actually written as a part of FubuMVC but is available as a stand alone library. HtmlTags provides a much cleaner syntax for writing HTML. There are classes for most of the major tags and it's trivial to create additional ones by inheriting from HtmlTag. There are also methods on each tag for the common attributes. For instance, FormTag has an Action() method. The SelectTag class allows you to set the default option or first option independent from adding other options. With TagBuilder there isn't even an abstraction for building selects! The project is open source and always improving. I'll hopefully find time to submit some of my own enhancements soon.   Tips 1) It's best not to have insanely overloaded html helpers. Use fluent builders. 2) In html helpers, return the TagBuilder/tag itself (not a string!) so that you can continue to add attributes outside the helper; see my first sample above. 3) Create a static entry point into your builders. I created a static Tags class that gives me access all the HtmlTag classes I need. This way I don't clutter my code with "new" keywords. eg. Tags.Div returns a new DivTag instance. 4) If you find yourself doing something a lot, create an extension method for it. I created a Nest() extension method that reads much more fluently than the AddChildren() method. It also accepts a params array of tags so I can very easily nest many children.   I hope you have found this post helpful. Join me in my war against HTML literals! I’ll have some more samples of how I use HtmlTags in future posts.

  Read the article

• ASP.NET Web Forms Extensibility: Handler Factories

  - by Ricardo Peres

  An handler factory is the class that implements IHttpHandlerFactory and is responsible for instantiating an handler (IHttpHandler) that will process the current request. This is true for all kinds of web requests, whether they are for ASPX pages, ASMX/SVC web services, ASHX/AXD handlers, or any other kind of file. Also used for restricting access for certain file types, such as Config, Csproj, etc. Handler factories are registered on the global Web.config file, normally located at %WINDIR%\Microsoft.NET\Framework<x64>\vXXXX\Config for a given path and request type (GET, POST, HEAD, etc). This goes on section <httpHandlers>. You would create a custom handler factory for a number of reasons, let me list just two: A centralized place for using dependency injection; Also a centralized place for invoking custom methods or performing some kind of validation on all pages. Let’s see an example using Unity for injecting dependencies into a page, suppose we have this on Global.asax.cs: 1: public class Global : HttpApplication 2: { 3: internal static readonly IUnityContainer Unity = new UnityContainer(); 4: 5: void Application_Start(Object sender, EventArgs e) 6: { 7: Unity.RegisterType<IFunctionality, ConcreteFunctionality>(); 8: } 9: } We instantiate Unity and register a concrete implementation for an interface, this could/should probably go in the Web.config file. Forget about its actual definition, it’s not important. Then, we create a custom handler factory: 1: public class UnityPageHandlerFactory : PageHandlerFactory 2: { 3: public override IHttpHandler GetHandler(HttpContext context, String requestType, String virtualPath, String path) 4: { 5: IHttpHandler handler = base.GetHandler(context, requestType, virtualPath, path); 6: 7: //one scenario: inject dependencies 8: Global.Unity.BuildUp(handler.GetType(), handler, String.Empty); 9:  10: return (handler); 11: } 12: } It inherits from PageHandlerFactory, which is .NET’s included factory for building regular ASPX pages. We override the GetHandler method and issue a call to the BuildUp method, which will inject required dependencies, if any exist. An example page with dependencies might be: 1: public class SomePage : Page 2: { 3: [Dependency] 4: public IFunctionality Functionality 5: { 6: get; 7: set; 8: } 9: } Notice the DependencyAttribute, it is used by Unity to identify properties that require dependency injection. When BuildUp is called, the Functionality property (or any other properties with the DependencyAttribute attribute) will receive the concrete implementation associated with it’s type, as registered on Unity. Another example, checking a page for authorization. Let’s define an interface first: 1: public interface IRestricted 2: { 3: Boolean Check(HttpContext ctx); 4: } An a page implementing that interface: 1: public class RestrictedPage : Page, IRestricted 2: { 3: public Boolean Check(HttpContext ctx) 4: { 5: //check the context and return a value 6: return ...; 7: } 8: } For this, we would use an handler factory such as this: 1: public class RestrictedPageHandlerFactory : PageHandlerFactory 2: { 3: private static readonly IHttpHandler forbidden = new UnauthorizedHandler(); 4:  5: public override IHttpHandler GetHandler(HttpContext context, String requestType, String virtualPath, String path) 6: { 7: IHttpHandler handler = base.GetHandler(context, requestType, virtualPath, path); 8: 9: if (handler is IRestricted) 10: { 11: if ((handler as IRestricted).Check(context) == false) 12: { 13: return (forbidden); 14: } 15: } 16:  17: return (handler); 18: } 19: } 20:  21: public class UnauthorizedHandler : IHttpHandler 22: { 23: #region IHttpHandler Members 24:  25: public Boolean IsReusable 26: { 27: get { return (true); } 28: } 29:  30: public void ProcessRequest(HttpContext context) 31: { 32: context.Response.StatusCode = (Int32) HttpStatusCode.Unauthorized; 33: context.Response.ContentType = "text/plain"; 34: context.Response.Write(context.Response.Status); 35: context.Response.Flush(); 36: context.Response.Close(); 37: context.ApplicationInstance.CompleteRequest(); 38: } 39:  40: #endregion 41: } The UnauthorizedHandler is an example of an IHttpHandler that merely returns an error code to the client, but does not cause redirection to the login page, it is included merely as an example. One thing we must keep in mind is, there can be only one handler factory registered for a given path/request type (verb) tuple. A typical registration would be: 1: <httpHandlers> 2: <remove path="*.aspx" verb="*"/> 3: <add path="*.aspx" verb="*" type="MyNamespace.MyHandlerFactory, MyAssembly"/> 4: </httpHandlers> First we remove the previous registration for ASPX files, and then we register our own. And that’s it. A very useful mechanism which I use lots of times.

  Read the article

• Is this proper OO design for C++?

  - by user121917

  I recently took a software processes course and this is my first time attempting OO design on my own. I am trying to follow OO design principles and C++ conventions. I attempted and gave up on MVC for this application, but I am trying to "decouple" my classes such that they can be easily unit-tested and so that I can easily change the GUI library used and/or the target OS. At this time, I have finished designing classes but have not yet started implementing methods. The function of the software is to log all packets sent and received, and display them on the screen (like WireShark, but for one local process only). The software accomplishes this by hooking the send() and recv() functions in winsock32.dll, or some other pair of analogous functions depending on what the intended Target is. The hooks add packets to SendPacketList/RecvPacketList. The GuiLogic class starts a thread which checks for new packets. When new packets are found, it utilizes the PacketFilter class to determine the formatting for the new packet, and then sends it to MainWindow, a native win32 window (with intent to later port to Qt).1 Full size image of UML class diagram Here are my classes in skeleton/header form (this is my actual code): class PacketModel { protected: std::vector<byte> data; int id; public: PacketModel(); PacketModel(byte* data, unsigned int size); PacketModel(int id, byte* data, unsigned int size); int GetLen(); bool IsValid(); //len >= sizeof(opcode_t) opcode_t GetOpcode(); byte* GetData(); //returns &(data[0]) bool GetData(byte* outdata, int maxlen); void SetData(byte* pdata, int len); int GetId(); void SetId(int id); bool ParseData(char* instr); bool StringRepr(char* outstr); byte& operator[] (const int index); }; class SendPacket : public PacketModel { protected: byte* returnAddy; public: byte* GetReturnAddy(); void SetReturnAddy(byte* addy); }; class RecvPacket : public PacketModel { protected: byte* callAddy; public: byte* GetCallAddy(); void SetCallAddy(byte* addy); }; //problem: packets may be added to list at any time by any number of threads //solution: critical section associated with each packet list class Synch { public: void Enter(); void Leave(); }; template<class PacketType> class PacketList { private: static const int MAX_STORED_PACKETS = 1000; public: static const int DEFAULT_SHOWN_PACKETS = 100; private: vector<PacketType> list; Synch synch; //wrapper for critical section public: void AddPacket(PacketType* packet); PacketType* GetPacket(int id); int TotalPackets(); }; class SendPacketList : PacketList<SendPacket> { }; class RecvPacketList : PacketList<RecvPacket> { }; class Target //one socket { bool Send(SendPacket* packet); bool Inject(RecvPacket* packet); bool InitSendHook(SendPacketList* sendList); bool InitRecvHook(RecvPacketList* recvList); }; class FilterModel { private: opcode_t opcode; int colorID; bool bFilter; char name[41]; }; class FilterFile { private: FilterModel filter; public: void Save(); void Load(); FilterModel* GetFilter(opcode_t opcode); }; class PacketFilter { private: FilterFile filters; public: bool IsFiltered(opcode_t opcode); bool GetName(opcode_t opcode, char* namestr); //return false if name does not exist COLORREF GetColor(opcode_t opcode); //return default color if no custom color }; class GuiLogic { private: SendPacketList sendList; RecvPacketList recvList; PacketFilter packetFilter; void GetPacketRepr(PacketModel* packet); void ReadNew(); void AddToWindow(); public: void Refresh(); //called from thread void GetPacketInfo(int id); //called from MainWindow }; I'm looking for a general review of my OO design, use of UML, and use of C++ features. I especially just want to know if I'm doing anything considerably wrong. From what I've read, design review is on-topic for this site (and off-topic for the Code Review site). Any sort of feedback is greatly appreciated. Thanks for reading this.

  Read the article

• Five Things Learned at the BSR Conference in San Francisco on Nov 2nd-4th

  - by Evelyn Neumayr

  The BSR Conference 2011—“Redefining Leadership”—held from Nov 2nd to Nov 4th in San Francisco, with Oracle as one of the main sponsors, saw senior business executives, civil society representatives, and other experts from around the world gathering to share strategies and insights on the future of sustainability. The general conference sessions kicked off on November 2nd with a plenary address by former U.S. Vice President Al Gore. Other sessions were presented by CEOs of the caliber of Carl Bass (Autodesk), Brian Dunn (Best Buy), Carlos Brito (Anheuser-Busch InBev) and Ofra Strauss (Strauss Group). Here are five key highlights from the conference: 1.      The main leadership challenge is integrating sustainability into core business functions and overcoming short-termism. The “BSR GlobeScan State of Sustainable Business Poll 2011” - a survey of nearly 500 business leaders from 300 member companies - shows that 84% of respondents are optimistic that global businesses will embrace CSR/sustainability as part of their core strategies and operations in the next five years but consider integrating sustainability into their core business functions the key challenge. It is still difficult for many companies that are committed to the sustainability agenda to find investors that understand the long-term implications and as Al Gore said “Many companies are given the signal by the investors that it is the short term results that matter and that is a terribly debilitating force in the market.” 2.      Companies are required to address increasing compliance requirements and transparency in their supply chain, especially in relation with conflict minerals legislation and water management. The Dodd-Frank legislation, OECD guidelines, and the upcoming Securities and Exchange Commission (SEC) rules require companies to monitor upstream the sourcing of tin, tantalum, tungsten, and gold, but given the complexity of this issue companies need to collaborate and partner with peer companies in their industry as well as in other industries to understand how to address conflict minerals in their supply chains. The Institute of Public and Environmental Affairs’ (IPE) China Water Pollution Map enables the public to access thousands of environmental quality, discharge, and infraction records released by various government agencies. Empowered with this information, the public has the opportunity to place greater pressure on polluting companies to comply with environmental standards and create solutions to improve their performance. 3.      A new standard for reporting on supply chain greenhouse gas emissions is available. The New “Scope 3” Supply Chain Greenhouse Gas Inventory Standard, released on October 4th 2011, is the only international greenhouse gas emissions standard that accounts for the full lifecycle of a company’s products. It provides a framework for companies to account for indirect emissions outside of energy use, such as transportation, manufacturing, and distribution, and it incorporates both upstream and downstream impacts of a product. With key investors now listing supplier vulnerability to rising energy prices and disruptions of service as a key concern, greenhouse gas (GHG) management isn’t just for leading companies but a necessity for any business. 4.      Environmental, social, and corporate governance (ESG) reporting is becoming increasingly important to investors and other stakeholders. While European investors have traditionally driven the ESG agenda, U.S. investors are increasingly including ESG data in their analyses. This trend will likely increase as stakeholders continue to demand that an ESG lens be applied to their investments. Investors are increasingly looking to partner on sustainability, as they see the benefits of ESG providing significant returns on investment. 5.      Software companies are offering an increasing variety of solutions to help drive changes and measure performance internally, in supply chains, and across peer companies. The significant challenge is how to integrate different software systems to facilitate decision-making based on a holistic understanding of trade-offs. Jon Chorley, Chief Sustainability Officer and Vice President, Supply Chain Management Product Strategy at Oracle was a panelist in the “Trends in Sustainability Software” session and commented that, “How we think about our business decisions really comes down to how we think about cost. And as long as we don’t assign a cost to things that have an environmental impact or social impact, then we make decisions based on incomplete information. If we could include that in the process that determines ‘Is this product profitable? we would then have a much better decision.” For more information on BSR visit www.brs.org. You can also view highlights of the plenary session at http://www.bsr.org/en/bsr-conference/session-summaries/2011. Oracle is proud to be a sponsor of this BSR conference. By Elena Avesani, Principal Product Strategy Manager, Oracle          

  Read the article

• 7 Reasons for Abandonment in eCommerce and the need for Contextual Support by JP Saunders

  - by Tuula Fai

  Shopper confidence, or more accurately the lack thereof, is the bane of the online retailer. There are a number of questions that influence whether a shopper completes a transaction, and all of those attributes revolve around knowledge. What products are available? What products are on offer? What would be the cost of the transaction? What are my options for delivery? In general, most online businesses do a good job of answering basic questions around the products as the shopper engages in the online journey, navigating the product catalog and working through the checkout process. The needs that are harder to address for the shopper are those that are less concerned with product specifics and more concerned with deciding whether the transaction met their needs and delivered value. A recent study by the Baymard Institute [1] finds that more than 60% of ecommerce site visitors will abandon their shopping cart. The study also identifies seven reasons for abandonment out of the commerce process [2]. Most of those reasons come down to poor usability within the commerce experience. Distractions. External distractions within the shopper’s external environment (TV, Children, Pets, etc.) or distractions on the eCommerce page can drive shopper abandonment. Ideally, the selection and check-out process should be straightforward. One common distraction is to drive the shopper away from the task at hand through pop-ups or re-directs. The shopper engaging with support information in the checkout process should not be directed away from the page to consume support. Though confidence may improve, the distraction also means abandonment may increase. Poor Usability. When the experience gets more complicated, buyer’s remorse can set in. While knowledge drives confidence, a lack of understanding erodes it. Therefore it is important that the commerce process is streamlined. In some cases, the number of clicks to complete a purchase is lengthy and unavoidable. In these situations, it is vital to ensure that the complexity of your experience can be explained with contextual support to avoid abandonment. If you can illustrate the solution to a complex action while the user is engaged in that action and address customer frustrations with your checkout process before they arise, you can decrease abandonment. Fraud. The perception of potential fraud can be enough to deter a buyer. Does your site look credible? Can shoppers trust your brand? Providing answers on the security of your experience and the levels of protection applied to profile information may play as big a role in ensuring the sale, as does the support you provide on the product offerings and purchasing process. Does it fit? If it is a clothing item or oversized furniture item, another common form of abandonment is for the shopper to question whether the item can be worn by the intended user. Providing information on the sizing applied to clothing, physical dimensions, and limitations on delivery/returns of oversized items will also assist the sale. A photo alone of the item will help, as it answers some of those questions, but won’t assuage all customer concerns about sizing and fit. Sometimes the customer doesn’t want to buy. Prospective buyers might be browsing through your catalog to kill time, or just might not have the money to purchase the item! You are unlikely to provide any information in contextual support to increase the likelihood to buy if the shopper already has no intentions of doing so. The customer will still likely abandon. Ensuring that any questions are proactively answered as they browse through your site can only increase their likelihood to return and buy at a future date. Can’t Buy. Errors or complexity at checkout can be another major cause of abandonment. Good contextual support is unlikely to help with severe errors caused by technical issues on your site, but it will have a big impact on customers struggling with complexity in the checkout process and needing a question answered prior to completing the sale. Embedded support within the checkout process to patiently explain how to complete a task will help increase conversion rates. Additional Costs. Tax, shipping and other costs or duties can dramatically increase the cost of the purchase and when unexpected, can increase abandonment, particularly if they can’t be adequately explained. Again, a lack of knowledge erodes confidence in the purchase, and cost concerns in particular, erode the perception of your brand’s trustworthiness. Again, providing information on what costs are additive and why they are being levied can decrease the likelihood that the customer will abandon out of the experience. Knowledge drives confidence and confidence drives conversion. If you’d like to understand best practices in providing contextual customer support in eCommerce to provide your shoppers with confidence, download the Oracle Cloud Service and Oracle Commerce - Contextual Support in Commerce White Paper. This white paper discusses the process of adding customer support, including a suggested process for finding where knowledge has the most influence on your shoppers and practical step-by-step illustrations on how contextual self-service can be added to your online commerce experience. Resources: [1] http://baymard.com/checkout-usability [2] http://baymard.com/blog/cart-abandonment

  Read the article

• Why is my Ubuntu system not using the correct kernel?

  - by Brooks Moses

  We're having a bit of confusion on a Ubuntu remote system -- /boot/grub/menu.lst suggests the system should boot into kernel 2.6.35-30-generic, but it is actually running kernel 2.6.32-27-generic. Where should I look to start figuring out why this is happening and how to fix it? Specifically, /boot/grub/menu.lst has default 0 and the first entry is title Ubuntu 10.10, kernel 2.6.35-30-generic uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.35-30-generic root=UUID=67717ee3-cbf9-45d2- ae97-820256f4c4fd ro quiet splash initrd /boot/initrd.img-2.6.35-30-generic Further, I've confirmed that /boot/vmlinuz-2.6.35-30-generic and /boot/initrd.img-2.6.35-30-generic exist and have appropriate permissions. Meanwhile, uname -a returns: $ uname -a Linux cuda2 2.6.32-27-generic #49-Ubuntu SMP Thu Dec 2 00:51:09 UTC 2010 x86_64 GNU/Linux Edit: I've also tried re-running update-grub, and rebooting; no luck. Here's the full menu.lst, as requested by a commenter: # menu.lst - See: grub(8), info grub, update-grub(8) # grub-install(8), grub-floppy(8), # grub-md5-crypt, /usr/share/doc/grub # and /usr/share/doc/grub-legacy-doc/. ## default num # Set the default entry to the entry number NUM. Numbering starts from 0, and # the entry number 0 is the default if the command is not used. # # You can specify 'saved' instead of a number. In this case, the default entry # is the entry saved with the command 'savedefault'. # WARNING: If you are using dmraid do not use 'savedefault' or your # array will desync and will not let you boot your system. default 0 ## timeout sec # Set a timeout, in SEC seconds, before automatically booting the default entry # (normally the first entry defined). timeout 3 ## hiddenmenu # Hides the menu by default (press ESC to see the menu) hiddenmenu # Pretty colours #color cyan/blue white/blue ## password ['--md5'] passwd # If used in the first section of a menu file, disable all interactive editing # control (menu entry editor and command-line) and entries protected by the # command 'lock' # e.g. password topsecret # password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/ # password topsecret # # examples # # title Windows 95/98/NT/2000 # root (hd0,0) # makeactive # chainloader +1 # # title Linux # root (hd0,1) # kernel /vmlinuz root=/dev/hda2 ro # # # Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST ### BEGIN AUTOMAGIC KERNELS LIST ## lines between the AUTOMAGIC KERNELS LIST markers will be modified ## by the debian update-grub script except for the default options below ## DO NOT UNCOMMENT THEM, Just edit them to your needs ## ## Start Default Options ## ## default kernel options ## default kernel options for automagic boot options ## If you want special options for specific kernels use kopt_x_y_z ## where x.y.z is kernel version. Minor versions can be omitted. ## e.g. kopt=root=/dev/hda1 ro ## kopt_2_6_8=root=/dev/hdc1 ro ## kopt_2_6_8_2_686=root=/dev/hdc2 ro # kopt=root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro ## default grub root device ## e.g. groot=(hd0,0) # groot=67717ee3-cbf9-45d2-ae97-820256f4c4fd ## should update-grub create alternative automagic boot options ## e.g. alternative=true ## alternative=false # alternative=true ## should update-grub lock alternative automagic boot options ## e.g. lockalternative=true ## lockalternative=false # lockalternative=false ## additional options to use with the default boot option, but not with the ## alternatives ## e.g. defoptions=vga=791 resume=/dev/hda5 # defoptions=quiet splash ## should update-grub lock old automagic boot options ## e.g. lockold=false ## lockold=true # lockold=false ## Xen hypervisor options to use with the default Xen boot option # xenhopt= ## Xen Linux kernel options to use with the default Xen boot option # xenkopt=console=tty0 ## altoption boot targets option ## multiple altoptions lines are allowed ## e.g. altoptions=(extra menu suffix) extra boot options ## altoptions=(recovery) single # altoptions=(recovery mode) single ## controls how many kernels should be put into the menu.lst ## only counts the first occurence of a kernel, not the ## alternative kernel options ## e.g. howmany=all ## howmany=7 # howmany=all ## specify if running in Xen domU or have grub detect automatically ## update-grub will ignore non-xen kernels when running in domU and vice versa ## e.g. indomU=detect ## indomU=true ## indomU=false # indomU=detect ## should update-grub create memtest86 boot option ## e.g. memtest86=true ## memtest86=false # memtest86=true ## should update-grub adjust the value of the default booted system ## can be true or false # updatedefaultentry=false ## should update-grub add savedefault to the default options ## can be true or false # savedefault=false ## ## End Default Options ## title Ubuntu 10.10, kernel 2.6.35-30-generic uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.35-30-generic root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro quiet splash initrd /boot/initrd.img-2.6.35-30-generic title Ubuntu 10.10, kernel 2.6.35-30-generic (recovery mode) uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.35-30-generic root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro single initrd /boot/initrd.img-2.6.35-30-generic title Ubuntu 10.10, kernel 2.6.32-32-server uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.32-32-server root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro quiet splash initrd /boot/initrd.img-2.6.32-32-server title Ubuntu 10.10, kernel 2.6.32-32-server (recovery mode) uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.32-32-server root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro single initrd /boot/initrd.img-2.6.32-32-server title Ubuntu 10.10, kernel 2.6.32-27-generic uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.32-27-generic root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro quiet splash initrd /boot/initrd.img-2.6.32-27-generic title Ubuntu 10.10, kernel 2.6.32-27-generic (recovery mode) uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/vmlinuz-2.6.32-27-generic root=UUID=67717ee3-cbf9-45d2-ae97-820256f4c4fd ro single initrd /boot/initrd.img-2.6.32-27-generic title Chainload into GRUB 2 root 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/grub/core.img title Ubuntu 10.10, memtest86+ uuid 67717ee3-cbf9-45d2-ae97-820256f4c4fd kernel /boot/memtest86+.bin ### END DEBIAN AUTOMAGIC KERNELS LIST To add complication and joy to my life, this is a desktop machine in a remote datacenter; we don't have either local access or serial-console access. Suggestions?

  Read the article

• Running a Mongo Replica Set on Azure VM Roles

  - by Elton Stoneman

  Originally posted on: http://geekswithblogs.net/EltonStoneman/archive/2013/10/15/running-a-mongo-replica-set-on-azure-vm-roles.aspxSetting up a MongoDB Replica Set with a bunch of Azure VMs is straightforward stuff. Here’s a step-by-step which gets you from 0 to fully-redundant 3-node document database in about 30 minutes (most of which will be spent waiting for VMs to fire up). First, create yourself 3 VM roles, which is the minimum number of nodes you need for high availability. You can use any OS that Mongo supports. This guide uses Windows but the only difference will be the mechanism for starting the Mongo service when the VM starts (Windows Service, daemon etc.) While the VMs are provisioning, download and install Mongo locally, so you can set up the replica set with the Mongo shell. We’ll create our replica set from scratch, doing one machine at a time (if you have a single node you want to upgrade to a replica set, it’s the same from step 3 onwards): 1. Setup Mongo Log into the first node, download mongo and unzip it to C:. Rename the folder to remove the version – so you have c:\MongoDB\bin etc. – and create a new folder for the logs, c:\MongoDB\logs. 2. Setup your data disk When you initialize a node in a replica set, Mongo pre-allocates a whole chunk of storage to use for data replication. It will use up to 5% of your data disk, so if you use a Windows VM image with a defsault 120Gb disk and host your data on C:, then Mongo will allocate 6Gb for replication. And that takes a while. Instead you can create yourself a new partition by shrinking down the C: drive in Computer Management, by say 10Gb, and then creating a new logical disk for your data from that spare 10Gb, which will be allocated as E:. Create a new folder, e:\data. 3. Start Mongo When that’s done, start a command line, point to the mongo binaries folder, install Mongo as a Windows Service, running in replica set mode, and start the service: cd c:\mongodb\bin mongod -logpath c:\mongodb\logs\mongod.log -dbpath e:\data -replSet TheReplicaSet –install net start mongodb 4. Open the ports Mongo uses port 27017 by default, so you need to allow access in the machine and in Azure. In the VM, open Windows Firewall and create a new inbound rule to allow access via port 27017. Then in the Azure Management Console for the VM role, under the Configure tab add a new rule, again to allow port 27017. 5. Initialise the replica set Start up your local mongo shell, connecting to your Azure VM, and initiate the replica set: c:\mongodb\bin\mongo sc-xyz-db1.cloudapp.net rs.initiate() This is the bit where the new node (at this point the only node) allocates its replication files, so if your data disk is large, this can take a long time (if you’re using the default C: drive with 120Gb, it may take so long that rs.initiate() never responds. If you’re sat waiting more than 20 minutes, start another instance of the mongo shell pointing to the same machine to check on it). Run rs.conf() and you should see one node configured. 6. Fix the host name for the primary – *don’t miss this one* For the first node in the replica set, Mongo on Windows doesn’t populate the full machine name. Run rs.conf() and the name of the primary is sc-xyz-db1, which isn’t accessible to the outside world. The replica set configuration needs the full DNS name of every node, so you need to manually rename it in your shell, which you can do like this: cfg = rs.conf() cfg.members[0].host = ‘sc-xyz-db1.cloudapp.net:27017’ rs.reconfig(cfg) When that returns, rs.conf() will have your full DNS name for the primary, and the other nodes will be able to connect. At this point you have a working database, so you can start adding documents, but there’s no replication yet. 7. Add more nodes For the next two VMs, follow steps 1 through to 4, which will give you a working Mongo database on each node, which you can add to the replica set from the shell with rs.add(), using the full DNS name of the new node and the port you’re using: rs.add(‘sc-xyz-db2.cloudapp.net:27017’) Run rs.status() and you’ll see your new node in STARTUP2 state, which means its initializing and replicating from the PRIMARY. Repeat for your third node: rs.add(‘sc-xyz-db3.cloudapp.net:27017’) When all nodes are finished initializing, you will have a PRIMARY and two SECONDARY nodes showing in rs.status(). Now you have high availability, so you can happily stop db1, and one of the other nodes will become the PRIMARY with no loss of data or service. Note – the process for AWS EC2 is exactly the same, but with one important difference. On the Azure Windows Server 2012 base image, the MongoDB release for 64-bit 2008R2+ works fine, but on the base 2012 AMI that release keeps failing with a UAC permission error. The standard 64-bit release is fine, but it lacks some optimizations that are in the 2008R2+ version.

  Read the article

• ASP.NET WebAPI Security 4: Examples for various Authentication Scenarios

  - by Your DisplayName here!

  The Thinktecture.IdentityModel.Http repository includes a number of samples for the various authentication scenarios. All the clients follow a basic pattern: Acquire client credential (a single token, multiple tokens, username/password). Call Service. The service simply enumerates the claims it finds on the request and returns them to the client. I won’t show that part of the code, but rather focus on the step 1 and 2. Basic Authentication This is the most basic (pun inteneded) scenario. My library contains a class that can create the Basic Authentication header value. Simply set username and password and you are good to go. var client = new HttpClient { BaseAddress = _baseAddress }; client.DefaultRequestHeaders.Authorization = new BasicAuthenticationHeaderValue("alice", "alice"); var response = client.GetAsync("identity").Result; response.EnsureSuccessStatusCode();   SAML Authentication To integrate a Web API with an existing enterprise identity provider like ADFS, you can use SAML tokens. This is certainly not the most efficient way of calling a “lightweight service” ;) But very useful if that’s what it takes to get the job done. private static string GetIdentityToken() {     var factory = new WSTrustChannelFactory(         new WindowsWSTrustBinding(SecurityMode.Transport),         _idpEndpoint);     factory.TrustVersion = TrustVersion.WSTrust13;     var rst = new RequestSecurityToken     {         RequestType = RequestTypes.Issue,         KeyType = KeyTypes.Bearer,         AppliesTo = new EndpointAddress(Constants.Realm)     };     var token = factory.CreateChannel().Issue(rst) as GenericXmlSecurityToken;     return token.TokenXml.OuterXml; } private static Identity CallService(string saml) {     var client = new HttpClient { BaseAddress = _baseAddress };     client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("SAML", saml);     var response = client.GetAsync("identity").Result;     response.EnsureSuccessStatusCode();     return response.Content.ReadAsAsync<Identity>().Result; }   SAML to SWT conversion using the Azure Access Control Service Another possible options for integrating SAML based identity providers is to use an intermediary service that allows converting the SAML token to the more compact SWT (Simple Web Token) format. This way you only need to roundtrip the SAML once and can use the SWT afterwards. The code for the conversion uses the ACS OAuth2 endpoint. The OAuth2Client class is part of my library. private static string GetServiceTokenOAuth2(string samlToken) {     var client = new OAuth2Client(_acsOAuth2Endpoint);     return client.RequestAccessTokenAssertion(         samlToken,         SecurityTokenTypes.Saml2TokenProfile11,         Constants.Realm).AccessToken; }   SWT Authentication When you have an identity provider that directly supports a (simple) web token, you can acquire the token directly without the conversion step. Thinktecture.IdentityServer e.g. supports the OAuth2 resource owner credential profile to issue SWT tokens. private static string GetIdentityToken() {     var client = new OAuth2Client(_oauth2Address);     var response = client.RequestAccessTokenUserName("bob", "abc!123", Constants.Realm);     return response.AccessToken; } private static Identity CallService(string swt) {     var client = new HttpClient { BaseAddress = _baseAddress };     client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", swt);     var response = client.GetAsync("identity").Result;     response.EnsureSuccessStatusCode();     return response.Content.ReadAsAsync<Identity>().Result; }   So you can see that it’s pretty straightforward to implement various authentication scenarios using WebAPI and my authentication library. Stay tuned for more client samples!

  Read the article

• Using a Predicate as a key to a Dictionary

  - by Tom Hines

  I really love Linq and Lambda Expressions in C#.  I also love certain community forums and programming websites like DaniWeb. A user on DaniWeb posted a question about comparing the results of a game that is like poker (5-card stud), but is played with dice. The question stemmed around determining what was the winning hand.  I looked at the question and issued some comments and suggestions toward a potential answer, but I thought it was a neat homework exercise. [A little explanation] I eventually realized not only could I compare the results of the hands (by name) with a certain construct – I could also compare the values of the individual dice with the same construct. That piece of code eventually became a Dictionary with the KEY as a Predicate<int> and the Value a Func<T> that returns a string from the another structure that contains the mapping of an ENUM to a string.  In one instance, that string is the name of the hand and in another instance, it is a string (CSV) representation of of the digits in the hand. An added benefit is that the digits re returned in the order they would be for a proper poker hand.  For instance the hand 1,2,5,3,1 would be returned as ONE_PAIR (1,1,5,3,2). [Getting to the point] 1: using System; 2: using System.Collections.Generic; 3:   4: namespace DicePoker 5: { 6: using KVP_E2S = KeyValuePair<CDicePoker.E_DICE_POKER_HAND_VAL, string>; 7: public partial class CDicePoker 8: { 9: /// <summary> 10: /// Magical construction to determine the winner of given hand Key/Value. 11: /// </summary> 12: private static Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 13: map_prd2fn = new Dictionary<Predicate<int>, Func<List<KVP_E2S>, string>> 14: { 15: {new Predicate<int>(i => i.Equals(0)), PlayerTie},//first tie 16:   17: {new Predicate<int>(i => i > 0), 18: (m => string.Format("Player One wins\n1={0}({1})\n2={2}({3})", 19: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 20:   21: {new Predicate<int>(i => i < 0), 22: (m => string.Format("Player Two wins\n2={2}({3})\n1={0}({1})", 23: m[0].Key, m[0].Value, m[1].Key, m[1].Value))}, 24:   25: {new Predicate<int>(i => i.Equals(0)), 26: (m => string.Format("Tie({0}) \n1={1}\n2={2}", 27: m[0].Key, m[0].Value, m[1].Value))} 28: }; 29: } 30: } When this is called, the code calls the Invoke method of the predicate to return a bool.  The first on matching true will have its value invoked. 1: private static Func<DICE_HAND, E_DICE_POKER_HAND_VAL> GetHandEval = dh => 2: map_dph2fn[map_dph2fn.Keys.Where(enm2fn => enm2fn(dh)).First()]; After coming up with this process, I realized (with a little modification) it could be called to evaluate the individual values in the dice hand in the event of a tie. 1: private static Func<List<KVP_E2S>, string> PlayerTie = lst_kvp => 2: map_prd2fn.Skip(1) 3: .Where(x => x.Key.Invoke(RenderDigits(dhPlayerOne).CompareTo(RenderDigits(dhPlayerTwo)))) 4: .Select(s => s.Value) 5: .First().Invoke(lst_kvp); After that, I realized I could now create a program completely without “if” statements or “for” loops! 1: static void Main(string[] args) 2: { 3: Dictionary<Predicate<int>, Action<Action<string>>> main = new Dictionary<Predicate<int>, Action<Action<string>>> 4: { 5: {(i => i.Equals(0)), PlayGame}, 6: {(i => true), Usage} 7: }; 8:   9: main[main.Keys.Where(m => m.Invoke(args.Length)).First()].Invoke(Display); 10: } …and there you have it. :) ZIPPED Project

  Read the article

• Sort Data in Windows Phone using Collection View Source

  - by psheriff

  When you write a Windows Phone application you will most likely consume data from a web service somewhere. If that service returns data to you in a sort order that you do not want, you have an easy alternative to sort the data without writing any C# or VB code. You use the built-in CollectionViewSource object in XAML to perform the sorting for you. This assumes that you can get the data into a collection that implements the IEnumerable or IList interfaces.For this example, I will be using a simple Product class with two properties, and a list of Product objects using the Generic List class. Try this out by creating a Product class as shown in the following code:public class Product {  public Product(int id, string name)   {    ProductId = id;    ProductName = name;  }  public int ProductId { get; set; }  public string ProductName { get; set; }}Create a collection class that initializes a property called DataCollection with some sample data as shown in the code below:public class Products : List<Product>{  public Products()  {    InitCollection();  }  public List<Product> DataCollection { get; set; }  List<Product> InitCollection()  {    DataCollection = new List<Product>();    DataCollection.Add(new Product(3,        "PDSA .NET Productivity Framework"));    DataCollection.Add(new Product(1,        "Haystack Code Generator for .NET"));    DataCollection.Add(new Product(2,        "Fundamentals of .NET eBook"));    return DataCollection;  }}Notice that the data added to the collection is not in any particular order. Create a Windows Phone page and add two XML namespaces to the Page.xmlns:scm="clr-namespace:System.ComponentModel;assembly=System.Windows"xmlns:local="clr-namespace:WPSortData"The 'local' namespace is an alias to the name of the project that you created (in this case WPSortData). The 'scm' namespace references the System.Windows.dll and is needed for the SortDescription class that you will use for sorting the data. Create a phone:PhoneApplicationPage.Resources section in your Windows Phone page that looks like the following:<phone:PhoneApplicationPage.Resources>  <local:Products x:Key="products" />  <CollectionViewSource x:Key="prodCollection"      Source="{Binding Source={StaticResource products},                       Path=DataCollection}">    <CollectionViewSource.SortDescriptions>      <scm:SortDescription PropertyName="ProductName"                           Direction="Ascending" />    </CollectionViewSource.SortDescriptions>  </CollectionViewSource></phone:PhoneApplicationPage.Resources>The first line of code in the resources section creates an instance of your Products class. The constructor of the Products class calls the InitCollection method which creates three Product objects and adds them to the DataCollection property of the Products class. Once the Products object is instantiated you now add a CollectionViewSource object in XAML using the Products object as the source of the data to this collection. A CollectionViewSource has a SortDescriptions collection that allows you to specify a set of SortDescription objects. Each object can set a PropertyName and a Direction property. As you see in the above code you set the PropertyName equal to the ProductName property of the Product object and tell it to sort in an Ascending direction.All you have to do now is to create a ListBox control and set its ItemsSource property to the CollectionViewSource object. The ListBox displays the data in sorted order by ProductName and you did not have to write any LINQ queries or write other code to sort the data!<ListBox    ItemsSource="{Binding Source={StaticResource prodCollection}}"   DisplayMemberPath="ProductName" />SummaryIn this blog post you learned that you can sort any data without having to change the source code of where the data comes from. Simply feed the data into a CollectionViewSource in XAML and set some sort descriptions in XAML and the rest is done for you! This comes in very handy when you are consuming data from a source where the data is given to you and you do not have control over the sorting.NOTE: You can download this article and many samples like the one shown in this blog entry at my website. http://www.pdsa.com/downloads. Select “Tips and Tricks”, then “Sort Data in Windows Phone using Collection View Source” from the drop down list.Good Luck with your Coding,Paul Sheriff** SPECIAL OFFER FOR MY BLOG READERS **We frequently offer a FREE gift for readers of my blog. Visit http://www.pdsa.com/Event/Blog for your FREE gift!

  Read the article

• SSIS: Building SQL databases on-the-fly using concatenated SQL scripts

  - by DrJohn

  Over the years I have developed many techniques which help automate the whole SQL Server build process. In my current process, where I need to build entire OLAP data marts on-the-fly, I make regular use of a simple but very effective mechanism to concatenate all the SQL Scripts together from my SSMS (SQL Server Management Studio) projects. This proves invaluable because in two clicks I can redeploy an entire SQL Server database with all tables, views, stored procedures etc. Indeed, I can also use the concatenated SQL scripts with SSIS to build SQL Server databases on-the-fly. You may be surprised to learn that I often redeploy the database several times per day, or even several times per hour, during the development process. This is because the deployment errors are logged and you can quickly see where SQL Scripts have object dependency errors. For example, after changing a table structure you may have forgotten to change any related views. The deployment log immediately points out all the objects which failed to build so you can fix and redeploy the database very quickly. The alternative approach (i.e. doing changes in the database directly using the SSMS UI) would require you to check all dependent objects before making changes. The chances are that you will miss something and wonder why your app returns the wrong data – a common problem caused by changing a table without re-creating dependent views. Using SQL Projects in SSMS A great many developers fail to make use of SQL Projects in SSMS (SQL Server Management Studio). To me they are invaluable way of organizing your SQL Scripts. The screenshot below shows a typical SSMS solution made up of several projects – one project for tables, another for views etc. The key point is that the projects naturally fall into the right order in file system because of the project name. The number in the folder or file name ensures that the projects the SQL scripts are concatenated together in the order that they need to be executed. Hence the script filenames start with 100, 110 etc. Concatenating SQL Scripts To concatenate the SQL Scripts together into one file, I use notepad.exe to create a simple batch file (see example screenshot) which uses the TYPE command to write the content of the SQL Script files into a combined file. As the SQL Scripts are in several folders, I simply use several TYPE command multiple times and append the output together. If you are unfamiliar with batch files, you may not know that the angled bracket (>) means write output of the program into a file. Two angled brackets (>>) means append output of this program into a file. So the command-line DIR > filelist.txt would write the content of the DIR command into a file called filelist.txt. In the example shown above, the concatenated file is called SB_DDS.sql If, like me you place the concatenated file under source code control, then the source code control system will change the file's attribute to "read-only" which in turn would cause the TYPE command to fail. The ATTRIB command can be used to remove the read-only flag. Using SQLCmd to execute the concatenated file Now that the SQL Scripts are all in one big file, we can execute the script against a database using SQLCmd using another batch file as shown below: SQLCmd has numerous options, but the script shown above simply executes the SS_DDS.sql file against the SB_DDS_DB database on the local machine and logs the errors to a file called SB_DDS.log. So after executing the batch file you can simply check the error log to see if your database built without a hitch. If you have errors, then simply fix the source files, re-create the concatenated file and re-run the SQLCmd to rebuild the database. This two click operation allows you to quickly identify and fix errors in your entire database definition.Using SSIS to execute the concatenated file To execute the concatenated SQL script using SSIS, you simply drop an Execute SQL task into your package and set the database connection as normal and then select File Connection as the SQLSourceType (as shown below). Create a file connection to your concatenated SQL script and you are ready to go.   Tips and TricksAdd a new-line at end of every fileThe most common problem encountered with this approach is that the GO statement on the last line of one file is placed on the same line as the comment at the top of the next file by the TYPE command. The easy fix to this is to ensure all your files have a new-line at the end.Remove all USE database statementsThe SQLCmd identifies which database the script should be run against.  So you should remove all USE database commands from your scripts - otherwise you may get unintentional side effects!!Do the Create Database separatelyIf you are using SSIS to create the database as well as create the objects and populate the database, then invoke the CREATE DATABASE command against the master database using a separate package before calling the package that executes the concatenated SQL script.    

  Read the article

• How-to hide the close icon for task flows opened in dialogs

  - by frank.nimphius

  Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} ADF bounded task flows can be opened in an external dialog and return values to the calling application as documented in chapter 19 of Oracle Fusion Middleware Fusion Developer's Guide for Oracle Application Development Framework11g: http://download.oracle.com/docs/cd/E15523_01/web.1111/b31974/taskflows_dialogs.htm#BABBAFJB Setting the task flow call activity property Run as Dialog to true and the Display Type property to inline-popup opens the bounded task flow in an inline popup. To launch the dialog, a command item is used that references the control flow case to the task flow call activity <af:commandButton text="Lookup" id="cb6"         windowEmbedStyle="inlineDocument" useWindow="true"         windowHeight="300" windowWidth="300"         action="lookup" partialSubmit="true"/> By default, the dialog that contains the task flow has a close icon defined that if pressed closes the dialog and returns to the calling page. However, no event is sent to the calling page to handle the close case. To avoid users closing the dialog without the calling application to be notified in a return listener, the close icon shown in the opened dialog can be hidden using ADF Faces skinning. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The following skin selector hides the close icon in the dialog af|panelWindow::close-icon-style{ display:none; } To learn about skinning, see chapter 20 of Oracle Fusion Middleware Web User Interface Developer's Guide for Oracle Application Development Framework http://download.oracle.com/docs/cd/E15523_01/web.1111/b31973/af_skin.htm#BAJFEFCJ However, the skin selector that is shown above hides the close icon from all af:panelWindow usages, which may not be intended. To only hide the close icon from dialogs opened by a bounded task flow call activity, the ADF Faces component styleClass property can be used. The af:panelWindow component shown below has a "withCloseWindow" style class property name defined. This name is referenced in the following skin selector, ensuring that the close icon is displayed af|panelWindow.withCloseIcon::close-icon-style{ display:block; } In summary, to hide the close icon shown for bounded task flows that are launched in inline popup dialogs, the default display behavior of the close icon of the af:panelWindow needs to be reversed. Instead to always display the close icon, the close icon is always hidden, using the first skin selector. To show the disclosed icon in other usages of the af:panelWindow component, the component is flagged with a styleClass property value as shown below <af:popup id="p1">   <af:panelWindow id="pw1" contentWidth="300" contentHeight="300"                                 styleClass="withCloseIcon"/> </af:popup> The "withCloseIcon" value is referenced in the second skin definition af|panelWindow.withCloseIcon::close-icon-style{ display:block; } The complete entry of the skin CSS file looks as shown below: af|panelWindow::close-icon-style{ display:none; } af|panelWindow.withCloseIcon::close-icon-style{ display:block; }

  Read the article

• Drawing on a webpage – HTML5 - IE9

  - by nmarun

  So I upgraded to IE9 and continued exploring HTML5. Now there’s this ‘thing’ called Canvas in HTML5 with which you can do some cool stuff. Alright what IS this Canvas thing anyways? The Web Hypertext Application Technology Working Group says this: “The canvas element provides scripts with a resolution-dependent bitmap canvas, which can be used for rendering graphs, game graphics, or other visual images on the fly.” The Canvas element has two only attributes – width and height and when not specified they take up the default values of 300 and 150 respectively. Below is what my HTML file looks like: 1: <!DOCTYPE html> 2: <html lang="en-US"> 3: <head> 4: <script type="text/javascript" src="CustomScript.js"></script> 5: <script src="jquery-1.4.4.js" type="text/javascript"></script 6:  7: <title>Draw on a webpage</title> 8: </head> 9: <body> 10: <canvas id="canvas" width="500" height="500"></canvas> 11: <br /> 12: <input type="submit" id="submit" value="Clear" /> 13: <h4 id="currentPosition"> 14: 0, 0 15: </h4> 16: <div id="mousedownCoords"></div> 17: </body> 18: </html> In case you’re wondering, this is not a MVC or any kind of web application. This is plain ol’ HTML even though I’m writing all this in VS 2010. You see this is a very simple, ‘gimmicks-free’ html page. I have declared a Canvas element on line 10 and a button on line 11 to clear the drawing board. I’m using jQuery / JavaScript show the current position of the mouse on the screen. This will get updated in the ‘currentPosition’ <h4> tag and I’m using the ‘mousedownCoords’ to write all the places where the mouse was clicked. This is what my page renders as: The rectangle with a background is our canvas. The coloring is due to some javascript (which we’ll see in a moment). Now let’s get to our CustomScript.js file. 1: jQuery(document).ready(function () { 2: var isFirstClick = true; 3: var canvas = document.getElementById("canvas"); 4: // getContext: Returns an object that exposes an API for drawing on the canvas 5: var canvasContext = canvas.getContext("2d"); 6: fillBackground(); 7:  8: $("#submit").click(function () { 9: clearCanvas(); 10: fillBackground(); 11: }); 12:  13: $(document).mousemove(function (e) { 14: $('#currentPosition').html(e.pageX + ', ' + e.pageY); 15: }); 16: $(document).mouseup(function (e) { 17: // on the first click 18: // set the moveTo 19: if (isFirstClick == true) { 20: canvasContext.beginPath(); 21: canvasContext.moveTo(e.pageX - 7, e.pageY - 7); 22: isFirstClick = false; 23: } 24: else { 25: // on subsequent clicks, draw a line 26: canvasContext.lineTo(e.pageX - 7, e.pageY - 7); 27: canvasContext.stroke(); 28: } 29:  30: $('#mousedownCoords').text($('#mousedownCoords').text() + '(' + e.pageX + ',' + e.pageY + ')'); 31: }); 32:  33: function fillBackground() { 34: canvasContext.fillStyle = '#a1b1c3'; 35: canvasContext.fillRect(0, 0, 500, 500); 36: canvasContext.fill(); 37: } 38:  39: function clearCanvas() { 40: // wipe-out the canvas 41: canvas.width = canvas.width; 42: // set the isFirstClick to true 43: // so the next shape can begin 44: isFirstClick = true; 45: // clear the text 46: $('#mousedownCoords').text(''); 47: } 48: })   The script only looks long and complicated, but is not. I’ll go over the main steps. Get a ‘hold’ of your canvas object and retrieve the ‘2d’ context out of it. On mousemove event, write the current x and y coordinates to the ‘currentPosition’ element. On mouseup event, check if this is the first time the user has clicked on the canvas. The coloring of the canvas is done in the fillBackground() function. We first need to start a new path. This is done by calling the beginPath() function on our context. The moveTo() function sets the starting point of our path. The lineTo() function sets the end point of the line to be drawn. The stroke() function is the one that actually draws the line on our canvas. So if you want to play with the demo, here’s how you do it. First click on the canvas (nothing visible happens on the canvas). The second click draws a line from the first click to the current coordinates and so on and so forth. Click on the ‘Clear’ button, to reset the canvas and to give your creativity a clean slate. Here’s a sample output: Happy drawing! Verdict: HTML5 and IE9 – I think we’re on to something big and great here!

  Read the article

• How to display a dependent list box disabled if no child data exist

  - by frank.nimphius

  A requirement on OTN was to disable the dependent list box of a model driven list of value configuration whenever the list is empty. To disable the dependent list, the af:selectOneChoice component needs to be refreshed with every value change of the parent list, which however already is the case as the list boxes are already dependent. When you create model driven list of values as choice lists in an ADF Faces page, two ADF list bindings are implicitly created in the PageDef file of the page that hosts the input form. At runtime, a list binding is an instance of FacesCtrlListBinding, which exposes getItems() as a method to access a list of available child data (java.util.List). Using Expression Language, the list is accessible with #{bindings.list_attribute_name.items} To dynamically set the disabled property on the dependent af:selectOneChoice component, however, you need a managed bean that exposes the following two methods //empty – but required – setter method public void setIsEmpty(boolean isEmpty) {} //the method that returns true/false when the list is empty or //has values public boolean isIsEmpty() {   FacesContext fctx = FacesContext.getCurrentInstance();   ELContext elctx = fctx.getELContext();   ExpressionFactory exprFactory =                          fctx.getApplication().getExpressionFactory();   ValueExpression vexpr =                       exprFactory.createValueExpression(elctx,                         "#{bindings.EmployeeId.items}",                       Object.class);   List employeesList = (List) vexpr.getValue(elctx);                        return employeesList.isEmpty()? true : false;      } If referenced from the dependent choice list, as shown below, the list is disabled whenever it contains no list data <! --  master list --> <af:selectOneChoice value="#{bindings.DepartmentId.inputValue}"                                  label="#{bindings.DepartmentId.label}"                                  required="#{bindings.DepartmentId.hints.mandatory}"                                   shortDesc="#{bindings.DepartmentId.hints.tooltip}"                                   id="soc1" autoSubmit="true">      <f:selectItems value="#{bindings.DepartmentId.items}" id="si1"/> </af:selectOneChoice> <! --  dependent  list --> <af:selectOneChoice value="#{bindings.EmployeeId.inputValue}"                                   label="#{bindings.EmployeeId.label}"                                      required="#{bindings.EmployeeId.hints.mandatory}"                                   shortDesc="#{bindings.EmployeeId.hints.tooltip}"                                   id="soc2" disabled="#{lovTestbean.isEmpty}"                                   partialTriggers="soc1">     <f:selectItems value="#{bindings.EmployeeId.items}" id="si2"/> </af:selectOneChoice>

  Read the article

< Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >